Canadian Forest Service Publications
Reduced vulnerability to hyperparasitism in nondiapause strains of Cotesia melanoscela (Ratzeburg) (Hymenoptera: Braconidae) 1995. Nealis, V.G.; Bourchier, R.S. Proceedings of the Entomological Society of Ontario 126: 29-35.
Issued by: Great Lakes Forestry Centre
Catalog ID: 21560
Availability: PDF (request by e-mail)
The vulnerability to predation and hyperparasitism of an introduced European strain of Cotesia melanoscela (Ratzeburg) (Hymenoptera: Braconidae) and an Asian strain of the parasitoid with a different cocoon morphology and no diapause state was compared in southern Ontario, Canada. The rates of predation and hyperparasitism were not related to cocoon morphology but were dependent on the length of time that cocoons were exposed to hyperparasitism in the field. The nondiapause characteristic of the Asian strain decreases its exposure time and hence reduces its vulnerability to hyperparasitism. Inundative release programs involving Cotesia spp. will be more effective using nondiapause strains of this parasitoid and by making releases as early as possible in the season to minimize their exposure to hyperparasitoids.